1、Designation: E1755 01 (Reapproved 2015)Standard Test Method forAsh in Biomass1This standard is issued under the fixed designation E1755; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parenth
2、eses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of ash,expressed as the mass percent of residue remaining after dryoxidation (oxidation at 575 6 25C), of hard
3、 and soft woods,herbaceous materials (such as switchgrass and sericea), agri-cultural residues (such as corn stover, wheat straw, andbagasse), wastepaper (such as office waste, boxboard, andnewsprint), acid and alkaline pretreated biomass, and the solidfraction of fermentation residues. All results
4、are reportedrelative to the 105C oven-dried mass of the sample. Forparticulate wood fuels, Test Method E1534 should be used.1.2 The values stated in SI units are to be regarded as thestandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It
5、 is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E1534 Test Method for Determination of Ash Content ofParticulate Wood FuelsE1756
6、 Test Method for Determination of Total Solids inBiomassE1757 Practice for Preparation of Biomass for Composi-tional Analysis3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 ashthe inorganic residue left after ignition at 575 625C.4. Significance and Use4.1 The ash content is a
7、n approximate measure of themineral content and other inorganic matter in biomass.4.2 The ash content is used in conjunction with other assaysto determine the total composition of biomass samples.5. Apparatus5.1 Ashing Crucibles, 50 mL, platinum crucibles arepreferred, but silica or porcelain crucib
8、les may be used.5.2 Muffle Furnace, an electric furnace is recommended forigniting the sample. The furnace should be fitted with anindicating pyrometer or thermocouple, so that the requiredtemperature of 575 6 25C can be maintained.5.3 Analytical Balance, sensitive to 0.1 mg.5.4 Desiccator, using an
9、hydrous calcium sulfate.5.5 Drying Oven, with temperature control of 105 6 2C.6. Test Specimen6.1 Test specimens suitable for analysis by this test methodare as follows:6.1.1 Prepared biomass samples that have been preparedaccording to Practice E1757.6.1.2 Biomass feedstocks, dried at 105C according
10、 to TestMethod E1756,6.1.3 Pretreated biomass, dried at 105C according to TestMethod E1756, and6.1.4 The solids fraction of fermentation residues, dried at105C according to Test Method E1756.6.2 The test specimen shall consist of approximately 0.5 to1.0 g of sample obtained in such a manner to ensur
11、e that it isrepresentative of the entire lot of material being tested.NOTE 1All samples should be ground or milled to reduce the size ofthe large pieces to less than 1 mm in diameter. The sample is then redriedat 105C prior to testing. Prepared biomass can be used in place of 105Cdried material, but
12、 the mass of the material must be corrected for itsmoisture content by using Test Method E1756, prior to calculating the ash.7. Procedure7.1 Mark a pan or crucible with a unique identification usinga porcelain marker, place it in the muffle furnace at 575 625C. Remove the pan or crucible from the fu
13、rnace, cool toroom temperature in a desiccator, and weigh to the nearest 0.11This test method is under the jurisdiction of ASTM Committee E48 onBioenergy and Industrial Chemicals from Biomass and is the direct responsibility ofSubcommittee E48.05 on Biomass Conversion.Current edition approved June 1
14、, 2015. Published July 2015. Originally approvedin 1995. Last previous edition approved in 2007 as E1755-01(2007)07. DOI:10.1520/E1755-01R15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volu
15、me information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1mg. For an aluminum pan, two hours of heating at 575 6 25Cwill be sufficient to bring the pan to constant
16、mass. With acrucible, however, the following procedure is used: place thecrucible in the furnace at 575 6 25C for 3 h. Remove thecrucible and place in a desiccator. Allow the crucible to cool toroom temperature and then weigh the crucible to the nearest0.1 mg. Record this mass. After weighing, retur
17、n the crucibleto the furnace for1hat5756 25C, cool again in thedesiccator, and reweigh. Repeat this step until the mass of thecrucible varies by less than 0.3 mg from the previous weighing.Record this final mass as the crucible tare mass, mcont. Keep thepan or crucible in a desiccator until used.7.2
18、 Weigh approximately 0.5 to 1.0 g, to the nearest 0.1 mg,of a test specimen into the tared pan or crucible. If the samplebeing analyzed is a test specimen dried at 105C, the sampleshould be stored in a desiccator until use. For a 105C driedtest sample, record the mass (container plus sample mass) as
19、the initial mass, mod. For prepared biomass samples preppedaccording to Practice E1757, record the mass (container plussample mass) as the initial mass, mar.NOTE 2For prepared biomass samples, it is recommend that samplesfor moisture determination should be weighed out at the same time as thesamples
20、 for the ash determination. If this is done at a later time it canintroduce an error in the calculation because ground biomass can rapidlygain or lose moisture when exposed to the atmosphere.7.3 Place the container and contents in the muffle furnaceand ignite at 575 6 25C for a minimum of 3 h, or un
21、til all thecarbon is eliminated. To avoid flaming, initially heat thesample to 250C at a rate of 10 K/min and hold for 30 minbefore increasing the temperature to 575 6 25C. Avoidheating above the maximum stated temperature.NOTE 3For test specimens containing high amounts of ash (greaterthan 5 % by m
22、ass), it will be necessary to increase the time in the furnaceto overnight to ensure complete elimination of the carbon. This ignitiontime period should not exceed 24 h.7.4 Taking care to protect the test container from strongdrafts to avoid mechanical loss of test specimen, remove thepan or crucibl
23、e with its contents to a desiccator, cool to roomtemperature, weigh to the nearest 0.1 mg, and record this mass.Repeat the heating for one hour periods until the mass aftercooling is constant to within 0.3 mg. Record the final mass ofthe ash, mash, as the container plus ash mass.8. Calculation8.1 Fo
24、r 105C dried materials, calculate the mass percent ofash, as follows:% ash 5 mash2 mcont!/mod2 mcont!# 3100 (1)where:% ash = mass percent of ash, based on 105C oven-driedmass of the sample,mash= mass of ash and container, g,mcont= tare mass of container, g, andmod= initial mass of 105C dried sample
25、and container,g.8.2 For a prepared biomass sample, prepped according toPractice E1757, the following calculation may be used toreport the mass percent of ash on a 105C dried mass basis,provided that the test specimen has already been analyzed formass percent total solids at 105C using Test Method E1
26、756.ms5 mar2 mcont! 3 T/100 (2)where:ms= mass of moisture-free solids in the prepared biomasssample, g,mar= initial mass of prepared biomass sample andcontainer, g,mcont= tare mass of container, g, andT = mass percent of total solids in sample, as determinedby Test Method E1756.% ash 5 mash2 mcont!/
27、ms# 3100 (3)where:% ash = mass percent of ash, based on 105C oven-driedmass of the sample,mash= mass of ash and container, g,mcont= tare mass of container, g, andms= mass of moisture-free solids in the prepared bio-mass sample, g.9. Report9.1 Report the result to two decimal places, as a masspercent
28、 of the samples 105C dried mass, and cite the basisused in the calculation.10. Precision and Bias10.1 SummaryIn comparing two single observations (Eq 1only), the difference should not exceed 10.4 % of the averageof the two observations in 95 out of 100 cases when bothobservations are taken by the sa
29、me well-trained operator usingthis procedure and specimens randomly drawn from the samesample of material.3,4The true value of ash can only be definedin terms of this procedure. Within this limitation, this testmethod has no known bias.10.2 Interlaboratory Test Data5In interlaboratory testingrun in
30、1993, randomly drawn samples of hybrid poplar weretested in each of five different laboratories. An operator in eachlaboratory tested duplicate specimens of the sample. Thecomponents of variance for ash results expressed as coeffi-cients of variation were calculated to be:Single-operator component 2
31、.67 % of the averageBetween-laboratory component 8.93 % of the averageNOTE 4The square roots of the components of variance are beingreported to express the variability in the appropriate units of measurerather than as the squares of those units of measure.10.3 Critical DifferencesFor the components
32、of variancereported in 10.2, two averages of observed values of the ashcontent should be considered significantly different at the 95 %3Technical Association of the Pulp and Paper Industry (TAPPI) StandardMethods, Method T 211 om-85, Ash in Wood and Pulp, 1991.4Vinzant, T.B., Ponfick, L., Nagle, N.J
33、., Ehrman, C.I., Reynolds, J.B., andHimmel, M.E., “SSF Comparison of Selected Woods From Southern Sawmills,”Applied Biochemical Biotechnology, 45/46, 1994, pp. 611626.5A copy of the supporting data for the interlaboratory test is available from theEthanol Project Chemical Analysis and Testing Task,
34、National Renewable ResearchLaboratory, 1617 Cole Boulevard, Golden, CO 80401-3393.E1755 01 (2015)2probability level if the difference equals or exceeds the criticaldifferences given in Table 1.10.4 Confidence LimitsFor the components of variancereported in 10.2, single averages of observed values ha
35、ve the95 % confidence limits given in Table 2.NOTE 5The values of the critical differences and confidence limitsshould be considered to be a general statement, particularly with respectto between-laboratory precision. Before a meaningful statement can bemade about two specific laboratories, the amou
36、nt of statistical bias, if any,between them must be established, with each comparison being based onrecent data obtained on specimens taken from a lot of material of the typebeing evaluated so as to be as nearly homogenous as possible and thenrandomly assigned to each of the laboratories.10.5 BiasTh
37、is procedure for measuring ash has no biasbecause the value of ash is only defined in terms of this testmethod. Changes in ashing parameters may vary the mass ofash recovered. Prolonged heating of the ash beyond the timesspecified in 7.3 may cause the volatilization of alkali elementsand cause a low
38、er ash content.11. Keywords11.1 agricultural residue; ash; biomass; fermentation resi-due; herbaceous; waste paper; woodASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are express
39、ly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised,
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41、end. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States.
42、Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secu
43、red from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 1 Critical Difference, Percent of Grand Average, For theConditions NotedA,BNumber of Observationsin Each AverageSingle OperatorPrecisionBetween-LaboratoryPrecision1 10.4 26.82 7.4 25.8AThe crit
44、ical differences were calculated with z = 1.960.BTo convert the values of the critical differences to units of measure, multiply thecritical differences by the average of the two specific sets of data being comparedand divide by 100.TABLE 2 Width of 95 % Confidence Limits, Percent of GrandAverage, F
45、or the Conditions NotedA,BNumber of Observationsin Each AverageSingle OperatorPrecisionBetween-LaboratoryPrecision1 7.4 19.02 5.2 18.2AThe critical differences were calculated with z = 1.960.BTo convert the values of the critical differences to units of measure, multiply thecritical differences by the average of the two specific sets of data being comparedand divide by 100.E1755 01 (2015)3
